fix(fleet): harden operator sends for release (#565)

packages/mosaic/src/commands/fleet.ts

@@ -1,6 +1,6 @@
 import { constants } from 'node:fs';
 import { access, copyFile, mkdir, readFile, writeFile } from 'node:fs/promises';
-import { homedir } from 'node:os';
+import { homedir, hostname } from 'node:os';
 import { dirname, join, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { spawn } from 'node:child_process';
@@ -158,11 +158,14 @@ export function buildAgentSendCommand(
   agentName: string,
   message: string,
   socketName = DEFAULT_SOCKET_NAME,
+  sourceLabel = getDefaultOperatorSourceLabel(),
 ): string[] {
   return [
     join(paths.tmuxToolsDir, 'agent-send.sh'),
     '-L',
     socketName,
+    '-S',
+    sourceLabel,
     '-s',
     agentName,
     '-m',
@@ -170,6 +173,11 @@ export function buildAgentSendCommand(
   ];
 }
 
+export function getDefaultOperatorSourceLabel(): string {
+  const shortHostname = hostname().split('.')[0] || 'localhost';
+  return `${shortHostname}:operator`;
+}
+
 export function buildAgentResetCommand(
   paths: FleetPaths,
   agentName: string,
@@ -384,15 +392,22 @@ export function registerFleetAgentCommands(
     .command('send <agent>')
     .description('Send a message to a local fleet agent')
     .requiredOption('--message <text>', 'Message text')
-    .action(async (agent: string, opts: { message: string }) => {
-      const roster = await loadRosterFromAgentCommand(agentCommand, deps.mosaicHome);
-      getRosterAgent(roster, agent);
-      const paths = resolveFleetPaths(resolveMosaicHomeFromCommand(agentCommand, deps.mosaicHome));
-      await runChecked(
-        runner,
-        buildAgentSendCommand(paths, agent, opts.message, roster.tmux.socketName),
-      );
-    });
+    .option('--source-label <label>', 'Source label for the message preamble')
+    .option('--source <label>', 'Alias for --source-label')
+    .action(
+      async (agent: string, opts: { message: string; sourceLabel?: string; source?: string }) => {
+        const roster = await loadRosterFromAgentCommand(agentCommand, deps.mosaicHome);
+        getRosterAgent(roster, agent);
+        const paths = resolveFleetPaths(
+          resolveMosaicHomeFromCommand(agentCommand, deps.mosaicHome),
+        );
+        const sourceLabel = opts.sourceLabel ?? opts.source ?? getDefaultOperatorSourceLabel();
+        await runChecked(
+          runner,
+          buildAgentSendCommand(paths, agent, opts.message, roster.tmux.socketName, sourceLabel),
+        );
+      },
+    );
 
   agentCommand
     .command('reset <agent>')